I like that it's size is large enough to have an ingame impact; I'm too busy working on my armies so I don't have much time or resources for Citadel or scratchbuilt terrain; this one will make a good proxy for now. The template and instructions are available at Ralf Engels homepage. The template is very simple, which makes it easy to experiment with. I'm thinking about adding battlement walls to this one.
I wish I had more time for Warhammer - but duty always comes first, at least the Emperor says so! I have way too many projects in the status of "nearly finished", including a Deff Dread, sternguard and bike squad and even some Tyranids - hopefully I'll finish some of these by Christmas. More paper terrain might come meanwhile - I'm having lovely papercraft saturdays with my girlfriend (really the only day in week I have time for the hobby at the moment).
Anyway, glory to the Emperor! I mean, have a nice day.